[Intel-gfx] [PATCH v4 3/6] drm/i915: prepare pipe for YCBCR420 output

Imre Deak imre.deak at intel.com
Tue Jul 18 18:12:22 UTC 2017


On Mon, Jul 17, 2017 at 08:06:24PM +0530, Shashank Sharma wrote:
> To get HDMI YCBCR420 output, the PIPEMISC register should be
> programmed to:
> - Generate YCBCR output (bit 11)
> - In case of YCBCR420 outputs, it should be programmed in full
>   blend mode to use the scaler in 5x3 ratio (bits 26 and 27)
> 
> This patch:
> - Adds definition of these bits.
> - Programs PIPEMISC for YCBCR420 outputs.
> - Adds readouts to compare HW and SW states.
> 
> V2: rebase
> V3: rebase
> V4: rebase
> V5: added r-b from Ander
> V6: Handle only YCBCR420 outputs (ville)
> V7: rebase
> V8: Addressed review comments from Ville
>     - Add readouts for state->ycbcr420 and 420 pixel_clock.
>     - Handle warning due to mismatch in clock for ycbcr420 clock.
>     - Rename PIPEMISC macros to match the Bspec.
>     - Add a debug print stating if YCBCR 4:2:0 output enabled.
>     Added r-b from Ville
> 
> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> Cc: Ander Conselvan de Oliveira <conselvan2 at gmail.com>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> 
> Reviewed-by: Ander Conselvan de Oliveira <conselvan2 at gmail.com>
> Reviewed-by: Ville Syrjala <ville.syrjala at linux.intel.com>
> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h      |  3 ++
>  drivers/gpu/drm/i915/intel_display.c | 55 ++++++++++++++++++++++++++++++++++--
>  2 files changed, 55 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index c712d01..6dfcdd3 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -5227,6 +5227,9 @@ enum {
>  
>  #define _PIPE_MISC_A			0x70030
>  #define _PIPE_MISC_B			0x71030
> +#define   PIPEMISC_YUV420_ENABLE	(1<<27)
> +#define   PIPEMISC_YUV420_MODE_BLEND	(1<<26)
> +#define   PIPEMISC_OUTPUT_YUV		(1<<11)

Missing the rename here requested by Ville.

>  #define   PIPEMISC_DITHER_BPC_MASK	(7<<5)
>  #define   PIPEMISC_DITHER_8_BPC		(0<<5)
>  #define   PIPEMISC_DITHER_10_BPC	(1<<5)
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index d78f1c2..788502a 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -6216,7 +6216,6 @@ static uint32_t ilk_pipe_pixel_rate(const struct intel_crtc_state *pipe_config)
>  	 * We only use IF-ID interlacing. If we ever use
>  	 * PF-ID we'll need to adjust the pixel_rate here.
>  	 */
> -

Extra w/s change.

>  	if (pipe_config->pch_pfit.enabled) {
>  		uint64_t pipe_w, pipe_h, pfit_w, pfit_h;
>  		uint32_t pfit_size = pipe_config->pch_pfit.size;
> @@ -8076,6 +8075,7 @@ static void haswell_set_pipemisc(struct drm_crtc *crtc)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
>  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> +	struct intel_crtc_state *config = intel_crtc->config;
>  
>  	if (IS_BROADWELL(dev_priv) || INTEL_INFO(dev_priv)->gen >= 9) {
>  		u32 val = 0;
> @@ -8101,6 +8101,12 @@ static void haswell_set_pipemisc(struct drm_crtc *crtc)
>  		if (intel_crtc->config->dither)
>  			val |= PIPEMISC_DITHER_ENABLE | PIPEMISC_DITHER_TYPE_SP;
>  
> +		if (config->ycbcr420) {
> +			val |= PIPEMISC_OUTPUT_YUV |
> +				PIPEMISC_YUV420_ENABLE |
> +				PIPEMISC_YUV420_MODE_BLEND;
> +		}
> +
>  		I915_WRITE(PIPEMISC(intel_crtc->pipe), val);
>  	}
>  }
> @@ -9170,6 +9176,10 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
>  		pipe_config->scaler_state.scaler_users &= ~(1 << SKL_CRTC_INDEX);
>  	}
>  
> +	if (IS_GEMINILAKE(dev_priv))
> +		pipe_config->ycbcr420 = I915_READ(PIPEMISC(crtc->pipe)) &
> +					PIPEMISC_YUV420_ENABLE;
> +
>  	power_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
>  	if (intel_display_power_get_if_enabled(dev_priv, power_domain)) {
>  		power_domain_mask |= BIT_ULL(power_domain);
> @@ -11377,6 +11387,9 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>  				      pipe_config->fdi_lanes,
>  				      &pipe_config->fdi_m_n);
>  
> +	if (pipe_config->ycbcr420)
> +		DRM_DEBUG_KMS("YCbCr 4:2:0 output enabled\n");
> +
>  	if (intel_crtc_has_dp_encoder(pipe_config)) {
>  		intel_dump_m_n_config(pipe_config, "dp m_n",
>  				pipe_config->lane_count, &pipe_config->dp_m_n);
> @@ -11704,6 +11717,22 @@ intel_modeset_update_crtc_state(struct drm_atomic_state *state)
>  	}
>  }
>  
> +static bool intel_420_clock_check(int clock1, int clock2)
> +{
> +	int diff;
> +
> +	if (clock1 == clock2 * 2)
> +		return true;
> +
> +	clock2 *= 2;
> +	diff = abs(clock1 - clock2);
> +
> +	if (((((diff + clock1 + clock2) * 100)) / (clock1 + clock2)) < 105)
> +		return true;
> +
> +	return false;
> +}
> +
>  static bool intel_fuzzy_clock_check(int clock1, int clock2)
>  {
>  	int diff;
> @@ -11832,6 +11861,18 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
>  		ret = false; \
>  	}
>  
> +#define PIPE_CONF_CHECK_CLOCK_420(name) \
> +	do { \
> +		if (!intel_420_clock_check(current_config->name, \
> +					   pipe_config->name)) { \
> +			pipe_config_err(adjust, __stringify(name), \
> +				  "(expected %i, found %i)\n", \
> +				  current_config->name, \
> +				  pipe_config->name); \
> +			ret = false; \
> +		} \
> +	} while (0)
> +
>  #define PIPE_CONF_CHECK_M_N(name) \
>  	if (!intel_compare_link_m_n(&current_config->name, \
>  				    &pipe_config->name,\
> @@ -11983,7 +12024,10 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
>  		}
>  
>  		PIPE_CONF_CHECK_I(scaler_state.scaler_id);
> -		PIPE_CONF_CHECK_CLOCK_FUZZY(pixel_rate);
> +		if (current_config->ycbcr420)
> +			PIPE_CONF_CHECK_CLOCK_420(pixel_rate);
> +		else
> +			PIPE_CONF_CHECK_CLOCK_FUZZY(pixel_rate);
>  	}
>  
>  	/* BDW+ don't expose a synchronous way to read the state */
> @@ -12009,7 +12053,11 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
>  	if (IS_G4X(dev_priv) || INTEL_GEN(dev_priv) >= 5)
>  		PIPE_CONF_CHECK_I(pipe_bpp);
>  
> -	PIPE_CONF_CHECK_CLOCK_FUZZY(base.adjusted_mode.crtc_clock);
> +	/* YCBCR 420 pixel clock is half of the actual mode */
> +	if (current_config->ycbcr420)
> +		PIPE_CONF_CHECK_CLOCK_420(base.adjusted_mode.crtc_clock);
> +	else
> +		PIPE_CONF_CHECK_CLOCK_FUZZY(base.adjusted_mode.crtc_clock);
>  	PIPE_CONF_CHECK_CLOCK_FUZZY(port_clock);
>  
>  #undef PIPE_CONF_CHECK_X
> @@ -12018,6 +12066,7 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
>  #undef PIPE_CONF_CHECK_FLAGS
>  #undef PIPE_CONF_CHECK_CLOCK_FUZZY
>  #undef PIPE_CONF_QUIRK
> +#undef PIPE_CONF_CHECK_CLOCK_420

We don't need to adjust things during compare. The dotclock is 2x
the port clock in case of YUV420, so all what's needed is

if (pipe_config->ycbcr420)                                          
	dotclock = pipe_config->port_clock * 2;

in ddi_get_clock() as Ville said.

Also, right now if I boot with these patches all 4k YUV420 modes will be
pruned on my monitor. This is caused by the monitor reporting a 300MHz
max tmds clock (which is the port clock limit) and the driver comparing
this against the dotclock which is double of this. So I needed

if (drm_mode_is_420_only(&connector->display_info, mode))                
	clock /= 2;

in intel_hdmi_mode_valid() to preserve these modes. Not sure why this
didn't come up earlier.

With that I see the YUV420 modes, but the initial modeset for the fb
console will result in the gray screen and some jitter. A following
modeset with the same mode will fix things; this is I think what Ville
also saw. Still trying to find the reason for this.

--Imre

>  
>  	return ret;
>  }
> -- 
> 2.7.4
> 


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